Abstract. Studies were conducted to establish the influence of the values of β-hydroxybutyric acid (ВНВА) and non-esterified fatty acids (NEFA) in the blood on the assessment of body condition score (BCS) of goats with subclinical ketosis (SCK). A total of 113 dairy goats with yearly milk yield of 680 L, in their 2nd to 3rd lactation and average body weight 50-60 кg were included in the study. The goats were divided in three groups: І group (n=27) – pregnant (from pre-partum days 15 to 0); ІІ group (n=28) – recently kidded (from postpartum days 0 to 15) and ІІІ group (n=58) – lactating (from postpartum days 30 to 45). It was established that the quantity of BHBA in goats from control groups I, II and III were between 0.17±0.11 mmol/l and 0.56±0.11 mmol/l. In goats from the three groups with SCK signs, blood BHBA was statistically significantly elevated vs control goats – from 0.88±0.11 mmol/l to 1.2±0.42 mmol/l (р<0.001). Blood ВНВА <0.8 mmol/l in goats are indicative a good transition from pregnancy to lactation, whereas an amount between 0.8 mmol/l and 1.6 mmol /l are indicative of the SCK. Blood BHBA concentrations indicative for clinical ketosis were not established in goats from the three groups (ВНВА <1.6 mmol/l). The body condition scores (BCS) of goats from the control groups was within the reference range – 2.45±0.3 – 2.85±0.2, whereas in goats with SCK – declines of varying degrees of reliability. In goats from the three groups with SCK signs, blood NEFA was statistically significantly elevated vs control groups.

Abstract. The objective of the present study is to make a comparative analysis of some basic qualitative parameters of rapeseed (Brassica napus) honey, monofloral (acacia Robinia pseudoacacia, sunflower Helianthus annuus, coriander Coriandrum sativum, lime Tilia sp.,) and multifloral honey. The study uses 26 samples of bee honey from different regions in the country. The physicochemical study was carried out at the Scientific Research Laboratory of Trakia University according to the harmonized methods of the International Honey Commission and the methods described in Bulgarian State Standard (BSS) 3050- 80 and Regulation No. 48/2003. The following indicators have been investigated: water, glucose, fructose and sucrose content (%); hydroxymethylfurfural content (HMF, mg/kg); electrical conductivity (mS/cm). Based on the results obtained for glucose (G) and fructose (F) content in the honey samples, the sum total of G + F has been calculated. It has been found that the average values of the studied physico-chemical parameters in all analyzed honey samples (incl. rapeseed honey) are within the tolerable limits according to national regulations. The established deviations from the requirements concerning HMF content in rapeseed honey samples can be explained by technological errors rather than by plant origin. By glucose content the analyzed rapeseed honey samples have values close to those of sunflower honey (over 30%). These results can explain the rapid crystallization of rapeseed and sunflower honey. The lowest average electrical conductivity values have been established for rapeseed and acacia honey, which is a characteristic feature of light coloured honey types. Rapeseed and multifloral honey have higher average active acidity value (pH) compared to the average for the monofloral honey types. Based on the results, it can be concluded that rapeseed bee honey (Brassica napus) is of quality, does not differ from the monofloral and multifloral types produced in our country, complies with national and international regulatory documents and can be used by humans for food and as preventive agent.

Abstract. Cellulases and hemicellulases are amount the main hydrolytic enzymes, involved in the bioconversion of lignocellulose material by microorganisms. Filamentous fungi of the genus Trichoderma are one of the most studied and good producer of cellulases and hemicellulases. The nutrients balance, especially carbon to nitrogen ratio, is one of the main factors of the biodegradation. The ability of 37 local isolates of Trichoderma sp. to produce cellulases and xylanase were tested in solid state cultivation on wheat straw as a substrate whit two variants: 1. the straw was only moistured with destilated water (CN 80:1); 2. the C:N ratio of the straw was adjusted to 30:1 using organic nitrogen amendment. There is a significant difference in the enzymatic activity of the isolates in their cultivation on straw with CN 80 and CN 30. The highest carboxymethylcellulase (CMCase) activity at CN 80 showed T1T (110.19U/ml), and in the variant at CN 30 – TD (369.07U/ml). The highest β-glucosidase activity on both variants CN 80 and CN 30 was established for TG (2743.1U/ml – 12679.9U/ml). The highest xylanase activity at CN 80 and CN 30 was measured on T4I (21311.5U/ml – 47937.5U/ml). After ONA addition, all enzymes activities have increased several times, indicating the enhancing effect of the additive. The average activity of CMCase increased 6.1 times, the average β – glucosidase activity increased 5.1 times, while the xylanase activity increased 4.9 times for all tested isolates. The increase in activity of the investigated enzymes showed different patterns.

Institute of Fisheries and Aquaculture, 4003, Plovdiv, Bulgaria
(Manuscript received 29 May 2017; accepted for publication 29 July 2017)

Abstract. The aim of this study is to examine the size selectivity of the pikeperch fed with one of the most widespread weed fish in fish farms, such as topmouth gudgeon (Pseudorasbora parva Temminck & Schlegel). Topmouth gudgeon (Pseudorasbora parva Temminck & Schlegel), separated in two size groups: large – group 1 (body weight of the specimens 8.63 ± 2.68 g, total length 9.58 ± 0.92 cm, and height of the body 2.06 ± 0.33 cm) and small – group 2 (body weight of the specimens 1.10 ± 0.36 g, average total body length of 5 ± 0.62 cm, and height of 0.85 ± 0.13 cm), were used for prey. The experiment was carried out under controlled laboratory conditions, in the course of 40 days, in 7 tanks. One pikeperch and 10 topmouth gudgeons from both size groups, in total 20 preys were placed in each tank. During the experimental period it was observed that pikeperch preferred to feed on smaller individuals, the difference in the number of consumed small and large fish is approximately 2 times (70 to 34, respectively).

(Manuscript received 12 April 2017; accepted for publication 20 June 2017)

Abstract. A feeding trial was conducted for sixty three (63) days (9 weeks) to evaluate the effects of feeding raw Senna obtusifolia seed meal (RSOSM) on haematological indices and serum biochemical parameters of broiler chickens. Six experimental diets were compounded for both the starter (23% crude protein – CP) and finisher (20% CP) phases of growth. The diets were formulated to contain 0, 5, 10, 15, 20 and 25% level of raw Senna obtusifolia seed meal replacing roasted soya bean weight for weight in T1, T2, T3, T4, T5 and T6, respectively. The 0% replacement level (T1) served as the control diet. The broiler chickens were managed on deep litter pens of 30 birds/2.22 m2, weighed and randomly allotted to the six (6) dietary treatments in a randomized complete block design (RCBD). Each treatment group consisted of thirty (30) broiler chicks replicated three times with ten (10) broiler chicks per replicate. Blood samples were collected from the wing vein at the end of the experiment using standard procedure and were analysed for haematological and biochemical profile. The outcome of this study revealed that the haematological indices were not significantly (P>0.05) affected by the dietary treatments. However, the blood chemistry was significantly (P<0.05) affected by the experimental diets. The total protein, albumin, globulin, and some electrolytes components were observed to be significantly (P<0.05) depressed as the level of RSOSM increased in the experimental diets. For instance, total protein was observed to reduce from 6.24g/dl in T1 to 3.6g/dl in T6. Electrolyte constituents such as calcium were similarly observed to reduce from 6.01 mmol/l in T1 to 1.15 mmol/l in T6. The serum enzymes and bilirubin were elevated as the level of RSOSM increases in the experimental diets. Aspartate amino transferase (AST) for instance increased from 8.27U/l in T1 to 23.18 U/l in T6. It can be concluded that incorporation of RSOSM beyond 5% in the diets of broiler chickens has adverse effects on blood parameters especially the biochemical parameters.

Abstract. The aim of the study was to evaluate the range of variation in chemical composition and in physical parameters of grain associated with feed quality of barley under the conditions of Southeast Bulgaria. A set of 21 winter six-rowed barley varieties from different geographic origins were investigated. The study was conducted in the Institute of Agriculture – Karnobat, during the period 2013/2014 – 2014/2015. Grain samples of the studied varieties were analysed for crude protein, lysine, starch, crude fat, crude ash, crude fiber, hectoliter weight and 1000 grains weight. The coefficient of variation was the highest in crude fat (21.52%) followed by lysine (9.52%). Low variation among varieties was found in nitrogen-free extract (CV=1.56%) and hectoliter weight (CV=2.77%). Correlations of crude protein with lysine, starch and crude fiber were negative. Starch content was positively associated with crude fat and hectoliter weight. Significant negative correlation of nitrogen-free extract with crude fat and crude fiber was found. Differences in chemical composition and physical parameters of grain indicated that the studied varieties can provide a source of germplasm for breeding winter barley varieties with improved feed quality.

1Department of Animal Science, University of Maiduguri, Maiduguri, Nigeria
2Department of Animal production, University of Ilorin, Ilorin, Nigeria

(Manuscript received 24 November 2016; accepted for publication 31 March 2017)

Abstract. The experiment was carried out to determine the effect of urea-fortified all-concentrate corncob diets on hematological indices and serum biochemical parameters of West African dwarf goats. Fifteen (15) West African dwarf goats (divided into 5 groups – one control and 4 experimental) with average weight of 9.33 kg were used for the study, which lasted 70 days. The animals were weighed and randomly assigned to five (5) treatments in a complete randomized design (CRD). The treatments were with different levels (%, 0, 1, 2, 3 and 4) of urea in corncob-based concentrate diets. Results of the hematological indices showed that Packed Cell Volume and Red Blood Cell values were significantly different (P<0.05) among treatment groups. Serum biochemistry showed that blood urea and albumen concentration were influenced (P<0.05) by dietary urea level. The other values of the blood biochemical indices and the parameters of hematology were similar (p>0.05) among dietary groups. The incorporation of urea in corncob diets has no negative effect on the animal and a 3% inclusion of urea showed good values for a healthy goat based on the blood biochemical and hematological indices.

(Manuscript received 24 March 2017; accepted for publication 30 May 2017)

Abstract. Investigation for determining the amount of in vitro gas production after feeding different groups of forages was performed at the Agricultural Institute-Stara Zagora. Forages from different regions were collected and analyzed for in vitro gas production at 24 h and 48 h by Ankom Technology®. The following parameters of the tested forages were determinated: Neutral detergent fibre (NDF, %), Acid detergent fibre (ADF, %), Digestibility of dry matter (DDM, %), Dry matter intakе (DMI, %) and Relative Feed Value (RFV, %). RFV was calculated on the base of DDM and DMI in comparison with alfalfa biomass in flowering stage. Collected feeds (46 samples) were divided in 11 groups on the base of their composition and structure – fibre component content. Depending on the amount of gas production forages can be divided in 3 groups: 1) Grain feeds generating the highest amount of gas – average 387.93 ml/g DM; 2) Combined feeds, fresh forages, complete feed mixtures – average 213.87- 245.15 ml/g DM; 3) Hay, silage, straw, complete feed mixtures + bioadditives – average 115.06 – 208.34 ml/g DM. Intensity of gas production in grain feeds was higher at 24 h, while on the opposite, was higher at 48 h in roughage feeds due to the different speed of degradation of feeds – concentrated had a very intensive and quick degradation, roughages – slow degradation. Supplementation of combined feeds with bioadditives Rumanol, Biolife, Bibor decreased the amount of gas production by 9.87% – 29.05%.

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p-ISSN: 1313-8820
e-ISSN: 1314-412X

About

Agricultural Science and Technology /AST/ was founded in 2009 by Faculty of Agriculture, Trakia University,
Stara Zagora, Bulgaria.
It’s is published in English in one volume of 4 issues per year, as a printed journal and in electronic form.

All issues in 2017 are printed with the financial support of the Project No DNP 05-21/20.12.2016, financed by Fund ‘Scientific Research’ grant Bulgarian scientific Periodicals.